基于折射率多维调制结构的空间光纤光栅理论与应用研究

Optical fiber refractive index modulation expands from limited core region to broad cladding spaces, and modulated structures transform from one-dimension to two- and three-dimensions. These changes not only provide innovation spaces for design and development of new fiber gratings, but also make it possible to optimize and upgrade the regulation of light by fiber gratings. Therefore, this project will carry out theoretical and practical research on spatial fiber gratings based on refractive index multi-dimensional modulation which include many systematical basic application studies on theoretical modeling, spectral characteristics simulation, mechanism exploration, mode regulation analysis, fabrication technology of fiber gratings, design and manufacture of related devices, and experimental measurement analysis, etc. The project detailed studies spatial fiber gratings based on refractive index tilted modulation and interlaced modulation as well as particular spatial fiber gratings derived from cascading. This project is a new research topic which has innovative significance in many respects of theory, experiment, technology, and application. The fresh ideas, new methods, novel structures, and innovative technologies have great reference value and basic scientific meanings on developing particular fiber gratings which possess special optical properties, integrated optical fiber photonic devices which have many excellent functions, and promoting fiber communications, fiber sensing, and internet of things.

光纤折射率调制由受限的纤芯区域向广阔的包层空间拓展，调制结构由一维向二维及三维的转变，不仅为设计和研制新型光纤光栅提供了创新空间，也使优化和提升光纤光栅调控光场功能成为可能。为此，本项目开展基于折射率多维调制结构的空间光纤光栅理论与应用研究，系统地对空间光纤光栅进行理论建模、光谱特性模拟、机理探索表征、模式调控分析、光栅写制技术、器件设计研制、实验测量分析等应用基础研究，重点研究基于折射率多维调制结构的空间倾斜光纤光栅和空间交错光纤光栅，以及由此级联衍生的特种空间光纤光栅。本项目是一个在理论、实验、技术及应用多方面具有创新意义的研究课题，其中的新思想、新方法、新结构及新技术，对于研制具有特殊光学性质的新型光纤光栅、集多种优异功能于一体的集成光纤光子器件，以及由此对光纤通信、光纤传感发展和物联网的推动，均具有重要的参考价值和基础科学意义。

构建了空间光纤光栅模型，建立了适用于纤芯和包层折射率调制的分析理论，模拟分析了熔锥型、少模型、相移型、扇形等折射率多维调制结构的空间光纤光栅光学特性；建立了正向、反向和正反结合的光栅结构设计方法，将光纤折射率调制结构由一维拓展为二维和三维，实现了光纤多维结构的设计和调制；探索并掌握了光纤折射率空间调制的关键技术，利用新技术研制出多种空间光纤光栅并进行了纤芯模式与包层模式的耦合、调控以及弯曲、扭转等矢量传感应用探索；系统地研究了正交、错位、熔锥、扇型、相移、少模、波状、多芯、复合、级联等多种类型的新型光纤光栅的机理表征、结构设计、特性分析、器件研制以及传感应用，取得了多项创新性研究成果。出版学术著作4部，发表学术论文45篇，接收待发表6篇，其中被SCI索引43篇，EI索引2篇；国内学术会议特邀报告2篇；获得发明专利授权2项和实用新型专利授权1项；培养博士7名，硕士8名，高质量地完成了基金任务书的各项研究内容。本项目研究中所提出的新思想、新结构以及建立的新方法、新技术等，不仅为设计和研制新型光纤光栅提供了新的方法和实现技术，也为进一步优化和提升光纤光栅调控光场功能以及拓展其工程化应用开辟了创新空间和应用领域。